Keywords
Fukushima, Chernobyl, radionuclides, rivers, lakes
Start Date
26-6-2018 10:40 AM
End Date
26-6-2018 12:00 PM
Abstract
Today, 7 years after the Fukushima accident, when emergency and short-term phases are over, the most relevant issue is long-term dynamics of radiocesium in the environment. Detailed analysis of Chernobyl data covering an extended period can become a foundation for long-term prediction of changes in environmental radioactive contamination in Fukushima. In our studies of the irrigation ponds in Okuma town, radiocesium (r-Cs) showed a persistent behavior and was characterized by regular seasonal variations: the r-Cs concentrations tend to grow in the summer and decrease in the winter. Similar behavior of r-Cs was observed in Chernobyl cooling pond for 30 years after the accident. It has been shown that long-term dynamics of radionuclides in the surface runoff and rivers is initially governed by their fixation on mineral particles, while later mainly by changes of the radionuclide activity concentration in the top soil layer. Both processes are diffusion-based and can be described by inverse square root of time function. The advantage of proposed “diffusion-based approach” is that all phases after the accident (short-, middle- and long-term) can be described by the same equation with the same parameters. Data sets for Chernobyl contaminated rivers Sakhan, Pripyat and Dneper as well as available data on r-Cs dynamics in Fukushima contaminated water bodies have been used to test the model. The proposed semi-empirical approach to describe r-Cs dynamics in rivers and lakes provides a tool for long-term predictions of rivers and lakes contamination in the future.
Empiric and semi-empiric modelling of radionuclide long-term dynamics in the soil-water environment: Fukushima and Chernobyl
Today, 7 years after the Fukushima accident, when emergency and short-term phases are over, the most relevant issue is long-term dynamics of radiocesium in the environment. Detailed analysis of Chernobyl data covering an extended period can become a foundation for long-term prediction of changes in environmental radioactive contamination in Fukushima. In our studies of the irrigation ponds in Okuma town, radiocesium (r-Cs) showed a persistent behavior and was characterized by regular seasonal variations: the r-Cs concentrations tend to grow in the summer and decrease in the winter. Similar behavior of r-Cs was observed in Chernobyl cooling pond for 30 years after the accident. It has been shown that long-term dynamics of radionuclides in the surface runoff and rivers is initially governed by their fixation on mineral particles, while later mainly by changes of the radionuclide activity concentration in the top soil layer. Both processes are diffusion-based and can be described by inverse square root of time function. The advantage of proposed “diffusion-based approach” is that all phases after the accident (short-, middle- and long-term) can be described by the same equation with the same parameters. Data sets for Chernobyl contaminated rivers Sakhan, Pripyat and Dneper as well as available data on r-Cs dynamics in Fukushima contaminated water bodies have been used to test the model. The proposed semi-empirical approach to describe r-Cs dynamics in rivers and lakes provides a tool for long-term predictions of rivers and lakes contamination in the future.
Stream and Session
Stream D: Modeling Environmental Fate of Contaminants, Human Well-being and Public Health
Session D3: Modelling Ecological Public Health Risks Across Scales